Recently, semiconductor devices are being developed to perform at high-speeds at a low voltage and semiconductors are being fabricated to increase the degree of integration thereof. Thus, the highly scaled patterns of highly integrated semiconductor devices have fine widths and may be spaced apart at small pitches.
Extreme ultraviolet (EUV) lithography technology has been introduced to form semiconductor devices having fine widths. The thickness of a photoresist in the etching of semiconductor devices using EUV lithography is one of important factors for improving productivity. Various techniques have been proposed to reduce the thickness of the photoresist required for pattern formation.